X-ray photoelectron spectroscopy (XPS)is highly adapt to characterize the chemical states of the surface of SiC samples. However, there were notable discrepancies in results for C ls spectra from fitting XPS data reported by using the method of fixed number and peak values (or full width half maximum) of peaks in different previous papers. In this paper, a novel XPS fitting method is proposed by adopting variable peak values (full width half maximum) and peak areas of peaks, and then the effects of number of peaks, functional types of peak and background on fitting results of the C 1s spectroscopy for SiC surface have been investigated. Comparing the XPS wide-scan spectroscopy and infrared glancing reflection absorption spectroscopy, optimal fitting parameters and fitting result for C 1s spectroscopy of SiC surface are determined. The binding energies of C 1s photoelectron spectroscopy obtained in this paper have the same values as that reported. All this establishes the basis for fitting narrow scan spectroscopy of elements and the investigation of chemical state structure of the surface of SiC and other materials.